1. Industrial useful field
This invention relates to an electrolyte feeder for battery in order to fill an electrolyte into a battery composed of plural cells.
2. Prior art
Various feeders for feeding an electrolyte into a battery composed of plural cells have conventionally been proposed. A newest one among them is disclosed in Japan Utility Model Publication KOKAI No. 63-93067. In this feeder; shell bodies 2 in each of which an electrolyte of cell unit is filled are interconnected in the same quantity as that of cell as illustrated by FIG. 3 for example, an openable thin film is formed on an edge of a filling tube 3, each shell body is sealed by the thin film, and an air groove 20 for feeding air to the shell body 2 is formed on an inner peripheral surface of the filling tube 3 as illustrated by FIG. 9.
To fill the electrolyte by using the feeder having such structure, the container is turned upside down to fit each filling tube 3 into each filling sleeve 19 of a recessed part (filling port 17) of a battery cover 14 as illustrated by FIG. 13. In a very compact battery such as that for a motor bicycle, however, an inside diameter of a filling hole 18 (filling passage) of the filling sleeve 19 is small (01 to 02 mm), the filling hole 18 is clogged with bubbles P due to a low water head and an influence of surface tension, and air becomes not displaced through the air groove 20. Therefore, such a case will arise that it becomes impossible to fill (feed) the electrolyte into the battery.
The above-mentioned low water head (abbreviated to "head" hereunder) will be described in details hereunder. FIG. 14 is the working principle explanatory view showing a head difference etc. when filling the electrolyte, in which the air groove 20 is shown in a simplified form by a position of an upper part of air groove in order for easy understanding of the head difference. In this FIG. 14, a head of .gamma.h' acts on a lower end of the filling hole 18 and a head of .gamma.h" acts on the air groove 20, so that a head which is substantially acting for filling the electrolyte will be given as follows: EQU .gamma.h'-.gamma.h"=.gamma.h
Namely, only an extremely small head will act on the electrolyte.
Therefore, as described above, in case of the filling hole 18 having a small inside diameter, bubbles will clog the hole by overcoming the foregoing head .gamma.h for some reason or others due to the influence of surface tension, so that such a case will arise that it becomes impossible to fill the electrolyte in the batery.